我最近发现onActivityResult已弃用。我们该怎么处理呢?
有什么替代方案吗?
我最近发现onActivityResult已弃用。我们该怎么处理呢?
有什么替代方案吗?
当前回答
我想出了如何从Kotlin的片段中正确地做到这一点,以捕获图像并处理返回的位图。在其他情况下也是一样的。
首先,您必须注册片段以侦听活动结果。这必须在初始化片段之前完成,这意味着创建一个成员变量,而不是在onCreate函数中初始化。
class DummyFragment : Fragment() {
//registering fragment for camera listener
private val takePhoto = registerForActivityResult(
ActivityResultContracts.StartActivityForResult()
) {
if (it.resultCode == Activity.RESULT_OK) {
val imageBitmap = it.data?.extras?.get("data") as Bitmap
// do your thing with the obtained bitmap
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
}
然后,像你通常做的那样调用摄像机意图。并使用上面创建的变量来启动意图。
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
someRandomButton.setOnClickListener {
val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
takePhoto.launch(takePictureIntent)
}
}
其他回答
您可以为Koltin使用扩展函数。例如:
//random utils file
fun Fragment.buildGetContentRequest(function: (Uri) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetContent()) {
function(it)
}
}
fun Fragment.buildTakePhotoRequest(function: (Boolean) -> Unit): ActivityResultLauncher<Uri> {
return this.registerForActivityResult(ActivityResultContracts.TakePicture()) {
function(it)
}
}
fun Fragment.buildSelectMultipleContentRequest(function: (MutableList<Uri>?) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetMultipleContents()) {
function(it)
}
}
然后在你的片段中像这样
//your actual fragment logic
class YourFragment : Fragment() {
//we can assign our request in init process
private val mRequestSelectFiles = buildSelectMultipleContentRequest {
onFilesSelected(it)
}
fun onSelectFiles() {
val mime = "*/*"
mRequestSelectFiles.launch(mime)
}
fun onFilesSelected(list: MutableList<Uri>?) {
//your logic
}
}
从现在开始,startActivityForResult()已经被弃用,所以使用new方法代替。
芬兰湾的科特林的例子
fun openActivityForResult() {
startForResult.launch(Intent(this, AnotherActivity::class.java))
}
val startForResult = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
result: ActivityResult ->
if (result.resultCode == Activity.RESULT_OK) {
val intent = result.data
// Handle the Intent
//do stuff here
}
}
似乎onActivityResult在超类中已弃用,但你在你的问题中没有提到超类名称和compileSdkVersion。
在Java和Kotlin中,只要添加@Deprecated,每个类或方法都可以标记为deprecated,所以检查你的超类,你可能扩展了一个错误的类。
当一个类被弃用时,它的所有方法也被弃用。
要看到一个快速的解决方案,点击弃用的方法,并按Ctrl+Q在Android工作室查看方法的文档,应该有一个解决方案。
在我使用androidx和API 29作为compileSdkVersion的项目中,此方法在活动和片段中不弃用
Kotlin版本的@Muntashir阿肯解决方案
class BetterActivityResult<Input, Result> private constructor(
caller : ActivityResultCaller,
contract : ActivityResultContract<Input, Result>,
var onActivityResult : ((Result) -> Unit)?,
) {
private val launcher : ActivityResultLauncher<Input> =
caller.registerForActivityResult(contract) { onActivityResult?.invoke(it) }
/**
* Launch activity, same as [ActivityResultLauncher.launch] except that it
* allows a callback
* executed after receiving a result from the target activity.
*/
/**
* Same as [.launch] with last parameter set to `null`.
*/
@JvmOverloads
fun launch(
input : Input,
onActivityResult : ((Result) -> Unit)? = this.onActivityResult,
) {
this.onActivityResult = onActivityResult
launcher.launch(input)
}
companion object {
/**
* Register activity result using a [ActivityResultContract] and an in-place
* activity result callback like
* the default approach. You can still customise callback using [.launch].
*/
fun <Input, Result> registerForActivityResult(
caller : ActivityResultCaller,
contract : ActivityResultContract<Input, Result>,
onActivityResult : ((Result) -> Unit)?,
) : BetterActivityResult<Input, Result> {
return BetterActivityResult(caller, contract, onActivityResult)
}
/**
* Same as [.registerForActivityResult] except
* the last argument is set to `null`.
*/
fun <Input, Result> registerForActivityResult(
caller : ActivityResultCaller,
contract : ActivityResultContract<Input, Result>,
) : BetterActivityResult<Input, Result> {
return registerForActivityResult(caller, contract, null)
}
/**
* Specialised method for launching new activities.
*/
fun registerActivityForResult(
caller : ActivityResultCaller,
) : BetterActivityResult<Intent, ActivityResult> {
return registerForActivityResult(caller, StartActivityForResult())
}
}
}
另一种方法是分3步完成。(考虑到你有一个startActivityForResult(0和onActivityResult()))
创建一个形式为var resultLauncher的变量:ActivityResultLauncher<Intent> 创建一个私有函数,在其中以这种基本格式初始化resultLauncher
resultLauncher=registerForActivityResult(ActivityResultContracts.StartActivityForResult()){result ->
// copy paste the code from the onActivityResult replacing resultcode to result.resultCode
if(result.resultcode==Activity.Result_OK){
val data=result.data // this data variable is of type intent and you can use it
}else{
//code if you do not get the data
}
}
使用startActivityForResult()返回行,并将其替换为resultLauncher.launch(intent)